Women’s health is much influenced by the female hormone estrogen. When estrogen levels drop during menopause, many women resort to hormone therapy. Hormone therapy can help women with hot flashes, mood swings, vaginal dryness and osteoporosis, but it also has some risks. Hormone therapy may increase their chance of heart attack, stroke, breast cancer and dementia. Isoflavones do not seem to have these risks. Isoflavones have an influence on the women’s health during menopause but also before and during the reproductive years, or pre-menopause period. A study showed that of the 1172 women participating in a six year study, the hysterectomy rate was lowest among the women whose diets contained the most soy foods. This study suggests that consuming soy foods, which contain isoflavones, seems to reduce the risk of fibroids and endometriosis.
Isoflavones and girls
The consumption of isoflavones during the puberty, when the female breast develops, appears to protect the woman later in life against cancer.
Studies show that women who ate weekly more than 3 portions of soy during adolescence showed a 40% reduced risk of breast cancer compared to those who did not consume soy. That’s why it’s important for girls to consume soy products or isoflavones supplements.
Isoflavones and menstrual cycle
Isoflavones could increase the length of the menstrual cycle and moderate alter steroid hormone levels. A British study found that women who were given 60 grams of soy a day had longer menstrual cycles. Asian women, who ingest more soy on a daily basis, generally have longer menstrual cycles than Western women. Research suggests that the low Japanese breast cancer mortality rate may, in part, be due to consumption of food containing soy isoflavones. Levels of steroid hormones and menstrual cycle duration are known risk factors for breast cancer. An increased menstrual cycle is beneficial because this results in less time that the breast cells are exposed to higher estrogen levels.
Isoflavones and menopause
During menopause the level of estrogen drops and causes common symptoms of menopause: hot flushes, insomnia, heavy sweating, mood swings, vaginal dryness and headaches.
Influence of soy based formula on women’s health
A cohort study by B.L.Strom of the Univrsity of Iowa showed that exposure of babies to soy based formula does not appear to result in health or reproductive problems later in live. The interviewed 811 men and women between 20 and 34 year who participated as baby in a controlled feeding study decades before. They found no statistically significant differences between the two groups in either women or men for 30 parameters. They only noticed a slightly longer menstrual bleeding duration and a greater discomfort with menstruation among women who were nursed as baby with soy based formula.
Isoflavones and breast cancer risk
Are soy isoflavones healthy or risky for breast cancer patients and survivors? Conflicting data from in-vivo and in-vitro studies have raised concern have raised concern about isoflavones and the promotion or propagation of estrogen-sensitive cancers. But recent case-control study and epidemiological studies show an inverse correlation between isoflavones intake and breast cancer risk. Not enough studies have been done to determine whether or not high concentrations of isoflavones from supplements may encourage the growth of breast cancer. If you’re taking soy supplements to treat menopausal symptoms, speak with your health professional about quantity of isoflavones that may be safe for you.
More literature about women’s health and isoflavones
Soy, isoflavones, and breast cancer risk in Japan. Journal of the National Cancer Institute, Vol. 95, No. 12, 906-913, June 18, 2003
Alternative treatments for menopause symptoms. Systematic review of scientific and lay literature. Can Fam Physician. 1998 Jun;44:1299-308
Chemoprevention of Breast Cancer, Proteomic Discovery of Genistein Action in the Rat Mammary Gland. Journal of Nutrition, 135:2953S-2959S, December 2005